Ultrahigh energy neutrino scattering onto relic light neutrinos in galactic halo as a possible source of highest energy extragalactic cosmic rays

The diffuse relic neutrinos with light mass are transparent to Ultrahigh energy (UHE) neutrinos at thousands EeV, born by photoproduction of pions by UHE protons on relic 2.73 K BBR radiation and originated in AGNs at cosmic distances. However these UHE $\nu$s may interact with those (mainly heaviest $\nu_{\mu_r}$, $\nu_{\tau_r}$ and respective antineutrinos) clustered into HDM galactic halos. UHE photons or protons, secondaries of $\nu\nu_r$ scattering, might be the final observed signature of such high-energy chain reactions and may be responsible of the highest extragalactic cosmic-ray (CR) events. The chain-reactions conversion efficiency, ramifications and energetics are considered for the October 1991 CR event at 320 EeV observed by the Fly's Eye detector in Utah. These quantities seem compatible with the distance, direction and power (observed at MeV gamma energies) of the Seyfert galaxy MCG 8-11-11. The $\nu\nu_r$ interaction probability is favoured by at least three order of magnitude with respect to a direct $\nu$ scattering onto the Earth atmosphere. Therefore, it may better explain the extragalactic origin of the puzzling 320 EeV event, while offering indirect evidence of a hot dark galactic halo of light (i.e., $m_\nu\sim$ tens eV) neutrinos, probably of tau flavour.Comment: 25 pages, 1 figure minor corrections, updated references. In press in AP

Possible Effects of the Existence of the 4th Generation Neutrino

The 4th generation of fermions predicted by the phenomenology of heterotic string models can possess new strictly conserved charge, which leads, in particular, to the hypothesis of the existence of the 4th generation massive stable neutrino. The compatibility of this hypothesis with the results of underground experiment DAMA searching for weakly interactive particles of dark matter and with the EGRET measurements of galactic gamma--background at energies above 1 GeV fixes the possible mass of the 4th neutrino at the value about 50 GeV. The possibility to test the hypothesis in accelerator experiments is considered. Positron signal from the annihilation of relic massive neutrinos in the galactic halo is calculated and is shown to be accessible for planned cosmic ray experiments.Comment: 10 pages, 4 PostScript figure, Latex2

Shadows of Relic Neutrino Masses and Spectra on Highest Energy GZK Cosmic Rays

The Ultra High Energy (UHE) neutrino scattering onto relic cosmic neutrinos in galactic and local halos offers an unique way to overcome GZK cut-off. The UHE nu secondary of UHE photo-pion decays may escape the GZK cut-off and travel on cosmic distances hitting local light relic neutrinos clustered in dark halos. The Z resonant production and the competitive W^+W^-, ZZ pair production define a characteristic imprint on hadronic consequent UHECR spectra. This imprint keeps memory both of the primary UHE nu spectra as well as of the possible relic neutrino masses values, energy spectra and relic densities. Such an hadronic showering imprint should reflect into spectra morphology of cosmic rays near and above GZK 10^{19}-10^{21}eV cut-off energies. A possible neutrino degenerate masses at eVs or a more complex and significant neutrino mass split below or near Super-Kamiokande \triangle m_{\nu_{SK}}= 0.1 eV masses might be reflected after each corresponding Z peak showering, into new twin unexpected UHECR flux modulation behind GZK energies: E_{p} sim 3(frac{triangle m_{\nu_{SK}}}/m_{\nu}10^{21}),eV. Other shadowsof lightest, nearly massless, neutrinos m_{nu_{2K} simeq 0.001eV simeq kT_{\nu}, their lowest relic temperatures, energies and densities might be also reflected at even higher energies edges near Grand Unification: E_{p} \sim 2.2(m_{\nu_{2K}/E_{\nu}})10^{23}, eV .Comment: 14 pages, 6 Figures,Invited Talk Heidelberg DARK 200

Thermal effects on the absorption of ultra-high energy neutrinos by the cosmic neutrino background

We use the formalism of finite-temperature field theory to study the interactions of ultra-high energy (UHE) cosmic neutrinos with the background of relic neutrinos and to derive general expressions for the UHE neutrino transmission probability. This approach allows us to take into account the thermal effects introduced by the momentum distribution of the relic neutrinos. We compare our results with the approximate expressions existing in the literature and discuss the influence of thermal effects on the absorption dips in the context of favoured neutrino mass schemes, as well as in the case of clustered relic neutrinos.Comment: 3 pages, 2 figures. Prepared for the Proceedings of the 9th International Conference on Topics in Astroparticle and Underground Physics (TAUP 2005), Zaragoza (Spain), September 10-14, 200

Primordial pairing and binding of superheavy charge particles in the early Universe

Primordial superheavy particles, considered as the source of Ultra High Energy Cosmic Rays (UHECR) and produced in local processes in the early Universe, should bear some strictly or approximately conserved charge to be sufficiently stable to survive to the present time. Charge conservation makes them to be produced in pairs, and the estimated separation of particle and antiparticle in such pair is shown to be in some cases much smaller than the average separation determined by the averaged number density of considered particles. If the new U(1) charge is the source of a long range field similar to electromagnetic field, the particle and antiparticle, possessing that charge, can form primordial bound system with annihilation timescale, which can satisfy the conditions, assumed for this type of UHECR sources. These conditions severely constrain the possible properties of considered particles.Comment: Latex, 4 pages. The final version to appear in Pis'ma ZhETF (the conditions for the primordial binding are specified, some refs added

Alle radici del welfare all'italiana : origini e futuro di un modello sociale squilibrato

La spesa pensionistica pi\uf9 elevata d\u2019Europa, limitate risorse destinate alla tutela delle famiglie, dei bambini e dei disoccupati, pochissime misure di contrasto alla povert\ue0. Dopo due decenni di riforme lo sbilanciamento \u201cfunzionale\u201d \u2013 verso il settore previdenziale \u2013 e la distorsione \u201cdistributiva\u201d \u2013 a favore degli occupati/insider rappresentano ancora temi sensibili nell\u2019attuale dibattito sulla riforma dello stato sociale in Italia. Ma quando \ue8 emerso l\u2019assetto di welfare che \ue8 oggi sotto la lente dei policy-makers? Quali sono state le tappe fondamentali che hanno portato al consolidarsi del \u201cwelfare all\u2019italiana\u201d, e quali dinamiche e fattori ne hanno rappresentato la spinta propulsiva? A partire dagli anni Ottanta, un\u2019articolata letteratura politologica e sociologica ha messo in luce le anomalie comparative del welfare \u201call\u2019italiana\u201d: manca per\uf2 una sistematica ed analitica ricostruzione storica che chiarisca sia il timing preciso sia le ragioni genetiche di quella doppia distorsione che caratterizza il nucleo centrale del welfare all\u2019italiana. In questa direzione, il volume mira a indagare, e successivamente interpretare, le radici del welfare state italiano tramite un\u2019analisi storico-evolutiva dalla fine del XIX secolo agli anni Settanta del XX. Pi\uf9 in dettaglio, il presente lavoro si propone tre obiettivi: i) caratterizzare sulla base di dati quantitativi e qualitativi sia la natura che l\u2019entit\ue0 degli squilibri funzionali e distributivi; ii) tracciare la loro genesi nel tempo individuandone i fattori che ne sono stati responsabili; iii) formulare, sulla scorta di una discussione critica della letteratura comparata sullo sviluppo del welfare state, ipotesi esplicative, proponendo infine un\u2019interpretazione in chiave storico-istituzionalista capace di rendere conto delle scelte effettuate dagli attori politici italiani negli snodi evolutivi in cui la doppia distorsione si \ue8 formata e consolidata. Il volume si articola su tre parti ed \ue8 composto da sette capitoli. Nella prima parte vengono poste le basi per l\u2019analisi empirica sia mettendo a fuoco la peculiarit\ue0 del welfare italiano in prospettiva comparata e tratteggiando il framework analitico (capitolo 1) sia illustrando le tappe di sviluppo della protezione sociale in Italia dalle origini alla II Guerra Mondiale (capitolo 2). La seconda e la terza parte sono invece dedicate allo studio del periodo che \ue8 considerato lo \u201csnodo critico\u201d per l\u2019emersione del welfare all\u2019italiana: gli anni Cinquanta (parte Due) e gli anni Sessanta (parte Tre). Entrambe le sezioni si aprono con l\u2019analisi e l\u2019interpretazione della traiettoria evolutiva del settore pensionistico e del Tfr (capitoli 3 e 5), per poi concentrarsi (cap. 4 e 6) sulla tutela della disoccupazione e i carichi famigliari, settori rimasti relativamente \u201catrofici\u201d. Il capitolo 7 conclude. L\u2019argomento centrale del volume \ue8 che, sullo sfondo di una policy legacy gi\ue0 favorevole all\u2019emergere di squilibri funzionali e distributivi, fattori cognitivi e soprattutto le peculiari caratteristiche della competizione politica \u2013 nel contesto di \u201cpluralismo polarizzato\u201d e \u201cdemocrazia bloccata\u201d degli anni Cinquanta-Sessanta \u2013 abbiamo giocato un ruolo decisivo nell\u2019orientare verso lo squilibrio il welfare state italiano